1. Field of the Invention
This invention relates to an apparatus or arrangement for driving at least one supplemental apparatus by power supplied from what is known as a "V-type" engine. Generally, a V-type automobile engine includes two, i.e., left and right, cylinder banks arranged in a V-shaped formation. The cylinder banks are disposed at a predetermined relative angle, and each cylinder bank is formed with a plurality of cylinders arranged in a row. The row of cylinders in one of the two cylinder banks is typically offset relative to the row of cylinders in the other of the cylinder banks. Offsetting the rows of cylinders relative to each other provides what is called a "dead" space, i.e., an unused volume, at one end of the cylinder block. This dead space is located in front of a cylinder bank including one of the two rows of cylinders. To briefly explain the structure of a known offset V-type automobile engine, reference is now made to FIG. 1. An engine body, generally designated by reference number 1, is provided with two rows of cylinders 5. More specifically, each row of cylinders is provided in one of left and right cylinder banks 3 and 4, which are either rigidly secured to or integrally formed with an engine block 2. The rows of cylinders 5 extend lengthwise of the engine body and parallel to a crankshaft 6. The row of cylinders 5 in the right cylinder bank 4 is offset rearward relative to the row of cylinders 5 in the left cylinder bank 3 in a lengthwise or axial direction of the engine body, indicated by an arrow X, in which the crankshaft 6 extends. A dead space or unused volume A, located in front of the end of the right cylinder block 4, is provided by offsetting the row of cylinders 5 in the right cylinder block 4. Generally a passage is provided for introducing engine coolant into the engine body 1. When the engine coolant passage is located in the dead portion A, a thermostat casing 7, having a thermostat for regulating the temperature of the engine coolant, is necessarily secured to the front end of the right cylinder bank 4.
2. Description of Related Art
A V-type engine of the type as shown in FIG. 1 is typically provided with a plurality of supplemental apparatuses, such as a water pump, an alternator, a compressor for an air conditioner, an oil pump for power steering, and a compressor for a mechanical supercharger. These supplemental apparatuses are driven by a drive belt or drive belts operationally coupling pulleys connected to respective drive shafts of the supplemental apparatuses and a crank pulley 8 secured to the front end of the crankshaft 6. If the number of such supplemental apparatuses is relatively large and/or all or some of the supplemental apparatuses have high driving loads, the supplemental apparatuses are typically divided into at least two groups. These two supplemental apparatus groups are separately disposed on opposite sides of the crankshaft 6 and driven independently by two independent drive belts. Such a supplemental apparatus drive arrangement is known from, for instance, Japanese Unexamined Patent Publication No. 60-230,503. Belt tensioning or tension regulating means for the drive belt of the supplemental apparatus drive arrangement generally must be provided so that the supplemental apparatuses are properly driven. Such a belt tensioning or tension regulating means is needed unless a position adjustable alternator, which can be adjusted in position with respect to the cylinder block 2 so as to regulate a drive belt tension, or some other similarly adjustable supplemental apparatus, is used.
When using two or more drive belts to drive the supplemental apparatuses, the drive belts and their associated belt tensioning means should be offset in the lengthwise direction of the crankshaft relative to each other. Consequently, the belt tensioning means for the foremost drive belt, i.e., the drive belt which is disposed closest to the front end of the automobile, is located at a relatively long distance from the front end of the cylinder block. It is, therefore, difficult to properly position and secure the belt tensioning means for the foremost drive belt to the front end of the cylinder block.